A group of soldiers apparently strayed into a section of the Demilitarized Zone (DMZ) by mistake, Seoul’s military has said FILE PHOTO: A North Korean guard post as seen from South Korea near the demilitarized zone (DMZ). © Chung Sung-Jun / Getty ImagesSouth Korean troops fired warning shots after a group of North Korean soldiers briefly crossed into the South’s portion of the Demilitarized Zone (DMZ) on Sunday, Seoul’s Joint Chiefs of Staff (JCS) has reported. The South Korean military believes that the incursion was unintentional, JCS spokesman Lee Sung-jun told journalists on Tuesday. While some of the soldiers were armed, others were carrying tools. The Military Demarcation Line (MDL) that bisects the DMZ is hard to notice in places due to thick undergrowth. After the southern side fired warning shots and broadcast a warning, the troops returned to the northern side of the line separating the rival neighbors. The DMZ was established after the Korean civil war of the 1950s ended in an armistice, and is considered one of the most heavily guarded borders on earth. It runs for 248km and is roughly 4km wide, with minefields, tank traps, and armed guards. “We were observing them even before they came near the MDL,” Lee said during a briefing. “It is assessed to be a simple violation, while they were moving for a task.” On Sunday, Seoul resumed broadcasting anti-Pyongyang propaganda across the DMZ after a six-year hiatus, but turned off the loudspeakers the next day. The move was a response to North Korea’s new practice of sending balloons carrying garbage across the border. The latest batch of plastic and scrap paper was released late on Sunday. READ MORE: North Korea launches more ‘filth’ balloons – Seoul South Korean activists have been sending anti-Pyongyang leaflets and other items in a similar fashion for years, hoping they would stir anti-government sentiment. North Korea has deployed some 1,600 airlifted trash packages since May 28 in its tit-for-tat action. Source